[Comparison of preoperative target ametropia and postoperative refraction for three types of lenses and intra-ocular differences (one pliable acrylic, one pliable PMMA-copolymer and one non-pliable PMMA) ].

In this retrospective study we compared the preoperative target ametropia, calculated with the SRK-T formula, with the postoperative refraction after extracapsular extraction by phacoemulsification and implantation of different posterior chamber lenses. The results show, for all 3 types of lenses, a postoperative refraction stability after the first month. According to our criteria, after 6 month, we have respectively for the non foldable PMMA lens, the PMMA-copolymere foldable and the acrylic foldable lens: 78%, 72% and 78% of good results; 13%, 28% and 9% of mild results and 9%, 0% and 13% of bad results. According to our criteria, the acrylic foldable lens has a tendency to move slightly backwards and the foldable PMMA-copolymere lens to move slightly frontwards. The non foldable lens gives pretty good results, however it is difficult to compare this lens with the 2 other lenses because of the large size of the incision.